A trailer unit for transporting tracked constructional machines

ABSTRACT

The invention concerns a trailer unit for use with a towing vehicle for transporting tracked constructional machines, such as excavators, said trailer unit including: a pair of wheeled carriages, respectively a left and a right wheeled carriages, adapted to be detachably connected to a pair of track frames, respectively a left and a right track frames, of a tracked constructional machine through first connecting means; a drawbar having a first end adapted to be detachably connected to a rear frame of the towing vehicle and a second end adapted to be detachably connected to a bottom frame of the tracked constructional machine through second connecting means.

TECHNICAL FILED

The invention relates to a trailer unit for use with a towing vehiclefor transporting tracked constructional machines.

The invention can be applied to several constructional machines, such asexcavators or mini excavators.

BACKGROUND

The transport of tracked constructional machines, in particularexcavators or mini excavators, is generally problematic. Indeed, thetracks of such machines do not permit their displacement from one siteto another site. It is thus necessary to use a trailer. However, if thecombined weight of the towing vehicle, the excavator and the trailerexceeds 4.25 tons, the road regulations impose that the driver of thetowing vehicle has a specific driving license. Furthermore, the towingvehicle must be sufficiently big to lodge other equipment of the trackedconstructional machines, such as buckets. The only possibility is thusto purchase or rent a dump truck or a large utility vehicle to tow theexcavator. These constraints limit the number of people who wish to renta mini excavator for their own needs.

The present invention aims to overcome the disadvantages of the priorart by providing a trailer unit that allows towing trackedconstructional machines without requiring an additional qualificationfor the user or the use of a towing vehicle whose purchase or rental isrelatively high.

SUMMARY

The invention concerns a trailer unit for use with a towing vehicle fortransporting tracked constructional machines, such as excavators, saidtrailer unit comprising:

-   -   a pair of wheeled carriages, respectively a left and a right        wheeled carriages, adapted to be detachably connected to a pair        of track frames, respectively a left and a right track frames,        of a tracked constructional machine through first connecting        means;    -   a drawbar having a first end adapted to be detachably connected        to a rear frame of the towing vehicle and a second end adapted        to be detachably connected to a bottom frame of the tracked        constructional machine through second connecting means;        wherein the first connecting means comprise a left, respectively        a right, locking plate pivotally connected to the left,        respectively the right, wheeled carriage, said left,        respectively said right, locking plate being movable between an        unlocking position, in which it can go through an aperture        formed in the left, respectively the right, track frame, and a        locking position, in which it cannot go through said aperture.

Thus configured, the trailer unit of the present invention allowsconverting a constructional machine into a trailer with a minimum weightincrease and with a minimum of assembly steps.

The trailer unit may also include one or more of the following features,taken alone or in combination.

According to one embodiment, the left, respectively the right, lockingplate has a rectangular or substantially rectangular shape.

According to a further embodiment, the left, respectively the right,locking plate is fixedly connected to a pivot axle, said left,respectively said right, locking plate moving from its unlockingposition to its locking position, or vice-versa, when a lever integralwith the pivot axle is moved along a rear-to-front direction.

According to a further embodiment, the first connecting means comprise apair of hook-shaped elements adapted to hook a pair of protruding studsof the left, respectively the right, track frame when the left,respectively the right, wheeled carriage is attached to the left,respectively the right, track frame.

According to a further embodiment, each wheeled carriage comprises apair of wheels, the wheels being aligned in a rear-to-front direction.

According to a further embodiment, each wheeled carriage comprises amudguard extending above the wheels.

According to a further embodiment, the second connecting means comprisea pin adapted to be received in through-holes of the drawbar andcorresponding trough-holes of the bottom frame of the trackedconstructional machine when the drawbar is attached to said bottomframe.

According to a further embodiment, the second connecting means compriselocking circlips connected at both ends of the pin, said lockingcirclips preventing the disconnection of the drawbar from the bottomframe.

According to a further embodiment, the drawbar is adapted to be receivedin a central opening of a dozer blade of the tracked constructionalmachine when the drawbar is attached to the bottom frame.

The invention also concerns a tracked constructional machine equippedwith a trailer unit according to the invention and comprising a pair oftrack frames, respectively a left and a right track frames, each trackframe being provided with an aperture and a pair of protruding studs.

According to one embodiment, the tracked constructional machine furthercomprises a dozer blade provided with a central opening receiving thesecond end of the drawbar.

Further advantages and advantageous features of the invention aredisclosed in the following description.

BRIEF DESCRIPTION OF THE DRAWINGS

With reference to the appended drawings, below follows a more detaileddescription of embodiments of the invention cited as examples.

In the drawings:

FIG. 1 is a perspective view of an excavator equipped with a trailerunit according to the invention;

FIG. 2 is a perspective view of the bottom frame of the excavatorillustrated in FIG. 1, equipped at one side with a wheeled carriage;

FIGS. 3 and 4 are perspective views of a wheeled carriage, when seenfrom the external and internal sides respectively;

FIG. 5 is a cross-sectional front view of the wheeled carriageillustrated in FIG. 3;

FIG. 5a is an enlarged view of a detail of FIG. 5;

FIG. 6 is is a top view of the detail illustrated in FIG. 5 a;

FIG. 7 is a perspective view of the wheel supporting member of thewheeled carriage illustrated in FIG. 3;

FIG. 8 is a perspective view of a connecting structure provided at eachlateral side of the bottom frame illustrated in FIG. 2;

FIG. 9 is a rear perspective view of a dozer blade provided at the frontside of the bottom frame illustrated in FIG. 2;

FIG. 10 is a perspective view of the dozer blade illustrated in FIG. 9,just before the attachment of the drawbar;

FIG. 11 is a front perspective view of the dozer blade illustrated inFIG. 9, when the excavator is not towed;

FIG. 12 is a view similar to FIG. 11, when the excavator is prepared tobe towed.

DETAILED DESCRIPTION OF EXAMPLE EMBODIMENTS OF THE INVENTION

The following description is merely exemplary in nature and is notintended to limit the present disclosure, application, or uses. Itshould be understood that throughout the drawings, correspondingreference numerals indicate like or corresponding parts or features.

FIG. 1 shows an excavator 100 equipped with a trailer unit 10 accordingto the invention. In the following paragraphs, the term “front” means“toward a front end of the excavator” and the term “rear” means “towarda rear end of the excavator”. The term “internal” means “toward thegravity center of the excavator” and the term “external” means “awayfrom the gravity center of the excavator”. The trailer unit 10 comprisesthree independent elements, respectively a drawbar 20 and a pair ofwheeled carriages 30. The drawbar 20 may advantageously comprise a frontend 22 and a rear end 24, the front end 22 being adapted to bedetachably connected to a towing vehicle (not shown) and the rear end 24being adapted to be detachably connected to the excavator 100. Theexcavator 100 comprises a cockpit 102 rotatably connected to a bottomframe 104, a pair of tracks 106 at its lateral sides and an articulatedarm 108 at its front side. The articulated arm 108 supports at least onetool 110, in particular a bucket, at its front end 109, said front end109 being advantageously attached to the drawbar 20 when the excavator100 is towed by a towing vehicle.

As illustrated in FIG. 2, the bottom frame 104 comprises a pair of trackframes 112 that support the tracks 106 and a dozer blade 114 at itsfront side. The dozer blade 114 may advantageously be pivotally movableabout a horizontal axis. The dozer blade 114 is provided with a centralopening 115, said central opening 115 being configured to receive therear end 24 of the drawbar 20 when the drawbar is connected to theexcavator 100, as illustrated in FIGS. 1 and 10. As illustrated in FIGS.9 and 10, the drawbar 20 can be attached to the bottom frame 104 when apair of through-holes 25 provided in the rear end 24 of the drawbar 20is aligned with corresponding through-holes 117 provided in a U-shapeattachment member 116 that extends rearward from the dozer blade 114 andwhen a pin 118 is received in said through holes 25 and saidcorresponding through-holes 117. A pair of locking circlips 119 mayadvantageously be connected at both ends of the pin 118 to preventdisconnection of the drawbar 20 from the attachment member 116. When theexcavator 100 is not towed, the central opening 115 may advantageouslybe covered by a masking element 120 formed by a tubular profile 121adapted to be detachably connected to the attachment structure 116 viathe pin 118 and the circlips 119, and by a front end 122 havingsubstantially the same dimension as the central opening 115, asillustrated in FIGS. 11 and 12.

In reference to FIGS. 3 and 4, it is illustrated a wheeled carriage 30of the trailer unit 10. Said wheeled carriage 30 comprises a wheelsupporting member 32, a pair of wheels 34 pivotally connected thereto,and a mudguard 36 fixedly connected to the wheel supporting member 32and extending above the wheels 34. When the wheeled carriage 30 isattached to the excavator 100, the wheels 32 are aligned in arear-to-front direction. Each wheel 32 may advantageously be equippedwith a drum brake 35.

As illustrated in FIGS. 5 and 7, the wheel supporting member 32comprises a L-shape profile 321 having a first flange 321 a extendingperpendicular to the rotation axes Ra of the wheels 34 and a secondflange 321 b extending perpendicular to the first flange 321 a, a pairof tubular profiles 322 extending at both ends of the L-shape profile321 and integral therewith, and a U-shape profile 323 extendingperpendicular to the second flange 321 b and integral therewith. Eachtubular profile 322 is adapted to receive an axle defining the rotationaxis Ra of a wheel 34, said axle being fixedly connected to the tubularprofile 322 through bolts. The U-shape profile 323 comprises a bottomwall 324 and a pair of lateral walls 325 at both sides thereof. Thebottom wall 324 comprises a circular cavity 326 that is aligned with acircular cavity 327 formed in an intermediate wall 328 that is parallelto the bottom wall 324 and integral with the lateral walls 325. Thelateral walls 325 are provided at their internally oriented sides withC-shape cut-outs 329. The role of the circular cavities 326, 327 and ofthe C-shape cut-outs 329 is detailed in the following paragraphs.

As illustrated in FIG. 2, each track frame 112 is provided with aU-shape connecting structure 124 protruding externally from the lateralsides thereof. As illustrated in FIG. 8, the connecting structure 124comprises a bottom plate 125 and a pair of lateral flanges 126 at bothsides thereof. Each lateral flange 126 is provided with a stud 128protruding along a rear-to-front direction from the external sidethereof. Said pair of protruding studs 128 is adapted to be receivedinside the C-shape cut-outs 329 and hooked by respective hook-shape topends 330 of said C-shape cut-outs 329 when the wheel supporting member32, and thus the wheeled carriage 30, is attached to a track frame 112.The bottom plate 125 comprises a rectangular aperture 127, said aperture127 having advantageously the same shape as a locking plate 38 that ispivotally connected to the wheel supporting member 32. When the wheeledcarriage 30 is attached to the track frame 112, the bottom plate 125 ofthe connecting structure 124 is positioned between the locking plate 38and the intermediate wall 328 of the wheel supporting member 32. Asillustrated in FIGS. 5, 5 a and 6, the locking plate 38 mayadvantageously be fixedly connected to a pivot axle 39 defining a pivotaxis Pa that is parallel to the rotation axes Ra of the wheels 34. Thepivot axle 39 extends through the circular cavities 326, 327. A lever 40fixedly connected to the pivot axle 39 permits to a user to pivotallymove the locking plate 38 around the pivot axis Pa when the lever 40 ismoved along a rear-to-front direction. The locking plate 38 can thus bemoved between two specific positions, respectively an unlockingposition, in which the locking plate 38 is aligned with the aperture127, and a locking position, as illustrated in FIG. 6, in which thelocking plate 38 is not aligned with the aperture 127. In the unlockingposition, the locking plate 38 can thus go through the aperture 127,thus permitting the disconnection of the wheeled carriage 30 from thetrack frame 112. On the contrary, in the locking position, the lockingplate 38 can not go through the aperture 127, thus preventing thedisconnection of the wheeled carriage 30 from the track frame 112. Thelocking plate 38 may advantageously be locked in said locking positionby a R-clip 41 that is introduced into a hole of the lever 40, saidR-clip 41 abutting against a lateral wall 325 of the U-shape profile323.

It is to be understood that the present invention is not limited to theembodiments described above and illustrated in the drawings; rather, theskilled person will recognize that many changes and modifications may bemade within the scope of the appended claims.

1. A trailer unit for use with a towing vehicle for transporting trackedconstructional machines, such as excavators, said trailer unitcomprising: a pair of wheeled carriages, respectively a left and a rightwheeled carriages, adapted to be detachably connected to a pair of trackframes, respectively a left and a right track frames, of a trackedconstructional machine through first connecting means; a drawbar havinga first end adapted to be detachably connected to a rear frame of thetowing vehicle and a second end adapted to be detachably connected to abottom frame of the tracked constructional machine through secondconnecting means; wherein the first connecting means comprise a left,respectively a right, locking plate pivotally connected to the left,respectively the right, wheeled carriage, said left, respectively saidright, locking plate being movable between an unlocking position, inwhich it can go through an aperture formed in the left, respectively theright, track frame, and a locking position, in which it cannot gothrough said aperture.
 2. The trailer unit according to claim 1, whereinthe left, respectively the right, locking plate has a rectangular orsubstantially rectangular shape.
 3. The trailer unit according to claim1, wherein the left, respectively the right, locking plate is fixedlyconnected to a pivot axle, said left, respectively said right, lockingplate moving from its unlocking position to its locking position, orvice-versa, when a lever fixedly connected to the pivot axle is movedalong a rear-to-front direction.
 4. The trailer unit according to claim1, wherein the first connecting means comprise a pair of hook-shapedelements adapted to hook a pair of protruding studs of the left,respectively the right, track frame when the left, respectively theright, wheeled carriage is attached to the left, respectively the right,track frame.
 5. The trailer unit according to claim 1, wherein eachwheeled carriage comprises a pair of wheels, the wheels being aligned ina rear-to-front direction.
 6. The trailer unit according to claim 5,wherein each wheeled carriage comprises a mudguard extending above thewheels.
 7. The trailer unit according to claim 1, wherein the secondconnecting means comprise a pin adapted to be received in through-holesof the drawbar and corresponding through-holes of the bottom frame ofthe tracked constructional machine when the drawbar is attached to saidbottom frame.
 8. The trailer unit according to claim 7, wherein thesecond connecting means comprise locking circlips connected at both endsof the pin, said locking circlips preventing the disconnection of thedrawbar from the bottom frame.
 9. The trailer unit according to claim 7,wherein the drawbar is adapted to be received in a central opening of adozer blade of the tracked constructional machine when the drawbar isattached to the bottom frame.
 10. A tracked constructional machineequipped with a trailer unit according to claim 1 and comprising a pairof track frames, respectively a left and a right track frames, eachtrack frame being provided with an aperture and a pair of protrudingstuds.
 11. The tracked constructional machine according to claim 10.further comprising a dozer blade provided with a central openingreceiving the second end of the drawbar.